diff --git a/src/main.cpp b/src/main.cpp
index 2aad3b9bb..e02ec515b 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2845,7 +2845,7 @@ namespace {
         hasher << hashBlock;
         hasher << blockundo;
         fileout << hasher.GetHash();
-
+fprintf(stderr,"hashBlock.%s hasher.%s\n",hashBlock.GetHex().c_str(),hasher.GetHash().GetHex().c_str());
         return true;
     }
 
@@ -2870,7 +2870,7 @@ namespace {
         hasher << hashBlock;
         hasher << blockundo;
         if (hashChecksum != hasher.GetHash())
-            return error("%s: Checksum mismatch %s vs %s", __func__,hashChecksum.GetHex().c_str(),hasher.GetHash().GetHex().c_str());
+            return error("%s: %s Checksum mismatch %s vs %s", __func__,hashBlock.GetHex().c_str(),hashChecksum.GetHex().c_str(),hasher.GetHash().GetHex().c_str());
 
         return true;
     }
@@ -3634,6 +3634,7 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
         return true;
 
     // Write undo information to disk
+    fprintf(stderr,"isNull %d vs isvalid %d nStatus %x\n",pindex->GetUndoPos().IsNull(),pindex->IsValid(BLOCK_VALID_SCRIPTS),(uint32_t)pindex->nStatus);
     if (pindex->GetUndoPos().IsNull() || !pindex->IsValid(BLOCK_VALID_SCRIPTS))
     {
         if (pindex->GetUndoPos().IsNull()) {
@@ -3644,7 +3645,6 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
                 fprintf(stderr,"ConnectBlock: unexpected null pprev\n");
             if (!UndoWriteToDisk(blockundo, pos, pindex->pprev->GetBlockHash(), chainparams.MessageStart()))
                 return AbortNode(state, "Failed to write undo data");
-
             // update nUndoPos in block index
             pindex->nUndoPos = pos.nPos;
             pindex->nStatus |= BLOCK_HAVE_UNDO;